| 摘要 |
808,734. Transistors; electrolytic jet-etching and jet-plating. TESZNER, S. Feb. 14, 1956 [Feb. 15, 1955; Feb. 4, 1956], No. 4540/56. Classes 37 and 41. A field effect transistor consists of a semiconductor rod 1 (Fig. 2), having metallic layers 5 and 6 on each end constituting source and drain electrodes, and a thinned central cylindrical portion 4 to 16 mils long and 2 to 6 mils in diameter, bearing a metallic layer 7 which constitutes the gate electrode and may be separated from the semi-conductor by a thininsulating layer. As shown in Fig. 2, signals from source B vary the potential of the gate electrode 7 which consists of a reverse biased area rectifying contact, to provide amplified signals in load 11. Fig. 10 shows apparatus for manufacturing the device in which an N- type germanium rod 18 of 3 to 30 ohm cms. resistivity is soldered to a nickel or bronze rod 19 forming one electrode which is mounted for rotation in a chuck 22. The other end of rod 18 is connected to a wire 24 engaging a droplet 25 of mercury so that current may be passed through rod 18 in series with a relay 33. Nozzle 28 associated with an etching solution H 2 SO 4 in container 30 operates to electrolytically etch away the centre portion of rod 18 while current from source 37 is passed between the rod and the electrolyte until the resistance along rod 18 is sufficient to de-energize relay 33. Contacts 55 of relay 33 when released reverse the polarity of source 37 and energize nozzle 29 which is associated with an electroplating solution of In 2 (SO 4 ) 3 plus H 2 SO 4 in container 31 so that the central portion is plated with a thin indium layer. Potentiometer 56 associated with source 37 is automatically varied so that the current is steadily reduced during the etching process. The metallic layer of the gate electrode may consist of In, Sn, Zn, Au, Pt or Woods metal and the semi-conductor body of Ge, Si or an A 3 B 5 intermetallic compound. If an insulating layer is provided between the semi-conductor and the gate electrode layer this may consist of an epoxy resin, or a layer of oxide may be produced by treatment of the semi-conductor surface with a solution of hydrogen peroxide and sodium carbonate. The advantages of a cylindrically shaped body according to the invention are compared with those of annular (Fig. 4) and rectangular (Fig. 5) shaped bodies. Fig. 14 shows the semi-conductor body 1 with electrodes 19 and 24 encased in a housing of epoxy resin and containing inert gas. Connection to the gate electrode is made by means of gold wire 43 and terminal 51. |
